When NumPy is built, information about system configuration is recorded, and is made available for extension modules using NumPy’s C API. These are mostly defined in numpyconfig.h (included in ndarrayobject.h). The public symbols are prefixed by NPY_*. NumPy also offers some functions for querying information about the platform in use.
numpyconfig.h
ndarrayobject.h
NPY_*
For private use, NumPy also constructs a config.h in the NumPy include directory, which is not exported by NumPy (that is a python extension which use the numpy C API will not see those symbols), to avoid namespace pollution.
config.h
The NPY_SIZEOF_{CTYPE} constants are defined so that sizeof information is available to the pre-processor.
NPY_SIZEOF_{CTYPE}
NPY_SIZEOF_SHORT
sizeof(short)
NPY_SIZEOF_INT
sizeof(int)
NPY_SIZEOF_LONG
sizeof(long)
NPY_SIZEOF_LONGLONG
sizeof(longlong) where longlong is defined appropriately on the platform.
NPY_SIZEOF_PY_LONG_LONG
NPY_SIZEOF_FLOAT
sizeof(float)
NPY_SIZEOF_DOUBLE
sizeof(double)
NPY_SIZEOF_LONG_DOUBLE
NPY_SIZEOF_LONGDOUBLE
sizeof(longdouble)
NPY_SIZEOF_PY_INTPTR_T
NPY_SIZEOF_INTP
Size of a pointer on this platform (sizeof(void *))
NPY_CPU_X86
NPY_CPU_AMD64
NPY_CPU_IA64
NPY_CPU_PPC
NPY_CPU_PPC64
NPY_CPU_SPARC
NPY_CPU_SPARC64
NPY_CPU_S390
NPY_CPU_PARISC
New in version 1.3.0.
CPU architecture of the platform; only one of the above is defined.
Defined in numpy/npy_cpu.h
numpy/npy_cpu.h
NPY_LITTLE_ENDIAN
NPY_BIG_ENDIAN
NPY_BYTE_ORDER
Portable alternatives to the endian.h macros of GNU Libc. If big endian, NPY_BYTE_ORDER == NPY_BIG_ENDIAN, and similarly for little endian architectures.
endian.h
Defined in numpy/npy_endian.h.
numpy/npy_endian.h
PyArray_GetEndianness
Returns the endianness of the current platform. One of NPY_CPU_BIG, NPY_CPU_LITTLE, or NPY_CPU_UNKNOWN_ENDIAN.
NPY_CPU_BIG
NPY_CPU_LITTLE
NPY_CPU_UNKNOWN_ENDIAN
NPY_LIKELY
NPY_UNLIKELY
NPY_UNUSED
NPY_INTERRUPT_H
NPY_SIGSETJMP
NPY_SIGLONGJMP
NPY_SIGJMP_BUF
NPY_SIGINT_ON
NPY_SIGINT_OFF